Granular material package and method of producing the same



July 7, l936- P. F. coLLlNs 2,046,366

GRANULAR MATERIAL PACKAGE AND METHOD OF PRODUCING THE SAME Filed Jan. 6, 1936 2 Sheets-Shea*l l @.ff/m J ATTORNEY July 7, 1936. P. F. COLLINS GRANULAR MATERIAL PACKAGE AND METHOD OF PRODUCING THE SAME Filed Jan. 6, 1956 2 Sheets-Sheet 2 1:' IST- E l. lIllllll/IIIIIIIIIIIl/lllllll/ :FILE- 5 #MW INVENTQR.

ATTORNEY Patented July 7, 1936 GRANULAR MATERIAL PACKAGE ANDv METHOD 0F PRODUCING THE SAIHE Paul Francis Collins, Columbus, Ohio, assignor to The Columbus Dental Manufacturing Company, Columbus, Ohio, a corporation Application January 6, 1936, Serial No. 57,829

10 Claims.

My invention relates to a package of granular material and method of making the same. It has to do particularly with a package oi dental investment compound and method of producing it, though it is not necessarily limited thereto, since the principles of my invention as regards both package and method may be applicable to other granular materials.

Dental investment compounds are made of varying constituents. Under present day practice, they usually embody siliceous refractory material, such as silica, cristobalite and the like, and a calcium sulphate binder, such as plaster of Paris or the like. In addition to these ingredients, other materials, such as boric acid, graphite, asbestos, ber, pumice stone, coloring matter, et cetera, have been used singly or in combination, though ordinarily in substantially smaller proportion than the above chief ingredients. One investment compound which I have invented and which is now on the market also embodies a copper powder.

These materials are commonly mixed together in powdered form and in such a way that the mixture is uniform throughout.v 'Ihis is important because of the fact that these dental investment compounds are sold to the trade in packages ranging from l pound to 100 pounds and relatively small portions thereof are, from time to time, withdrawn from the package by the dentist -or dental technician for the making of casting molds or for use in soldering operations. Each portion so withdrawn should possess its proper percentage of each ingredient initially used in mixing the compound. The necessity for this is illustrated by the fact that the dental investment compounds are sold to the dentist or laboratory technician with denite assurance, frequently printed upon the container, that they will possess given qualities, such as denite setting expansion, denite thermal expansion, definite setting time and definite crushing strength.

The importance of this is illustrated by the fact that under present day methods of precision casting of precious metal inlays, of precious metal against embedded metals and of other precious metal units, it is the practice to construct a casting mold of these dental investment compounds and to rely upon the combined setting and thermal expansion of the mold as a factor which will compensate for the shrinkage of the precious metal casting upon cooling. In other words, the

mold, upon subjection to the heating operations necessary as a preliminary to the casting operation, will have a cavity denitely larger than the (Cl. 20G-63.5)

above, the setting time and crushing strength l0 must be deinite and adequate in each mold and this is, of course, dependent upon the proper mixture of the ingredentsin each portion withdrawn by the dentist or laboratory technician for use.

In the prior art, considerable eiort has been l5 devoted to the proper mixing of the ingredients so that the relative percentages thereof will be uniform throughout upon the completion of the mixing operation. Prior to my invention, however, it has been customary to place the desired-.weight of the mixed compound in the container in which it is to be marketed in a loose state. Owing to the difference in nature of these different ingredients, they differ in grain size, in grain shape and in specic gravity and, in the main, these dille!- lences are unavoidable. Thus, when the oompound is placed in its container in its loose state, the ensuing handling and shipment inevitably results in such a stratification or migration of the di'erent materials that, by the' time the dentist or laboratory technician is ready to withdraw successive portions from the container, the compound is not in its originally mixed state, i. e., not uniformly mixed throughout the container. The result is that the successive portions of compounds wlthdrawn from the container will not have uniform percentages of the proper ingredients uniformly distributed throughout. Thus, one portion may have an excess of siliceous material and another portion may have an excess of calcium sulphate material and some portions will have more metal powder than others, while the other ingredients that may bein the compound will not be present in successive portions inthe proper proportions. The dentist or laboratory technician, therefore, could not reliably depend upon obtaining any accuracy of result in carrying out his technical operations and failures in obtainingproper results are for the reasons stated very commonly caused.

In the prior art, manufacturers have resorted to the crude practice of marking on the containerssuch instructions as Shake before using" or Stir before using. However, the mixing of the ingredients in a proper manner is a type of a. operation requiring the use of mechanical apparatus, and the steps normally taken by the dentist or laboratory technician in pursuance" of these instructions are insufilcient and inadequate to restore the compound toits initial properly mixedv state.

My .invention has to do with the provision of a package of dental investment compound which will remedy these drawbacks of the prior art.

l It has for its object the provision of such a package that thedental investment compound which has been properly mixed to provide the various factors.' such as proper setting expansion, proper thermal expansion. proper relative percentages of grain sizes, proper porosity, setting time and crushing strength will be retained` Y in such properly mixed condition until it reaches the dentist or laboratory technician and has been opened by him preliminary to its use in the l production of molds or in soldering operations.

' In`=its preferred form, my invention comprisesV a', package of dental investment compoimd whereinl the compound has been introduced into its container in a properly mixed state and hasl been subjected to the application of pressure tending to maintain it against the action of disturbing forces when the container is sealed sotliat all or substantially all danger of stratification and settling out of ingredients ,of the "40 compound under the normal conditions of handling and shipping is removed. It further con- `templates the closing of the container in such a way that the compressed compoimd is sub-' :jected either directly or indirectly in .pressure '-45 'from the container walls and closure of a kind and degree to maintain the compound in its "compressed state. It still further contemplates a novel method of producing the package.

-A preferred embodiment of my invention is s04 illustrated in the accompanying drawings' wherein similar characters of reference d'corresponding parts and wherein: Fig. 1. is a perspective view, partly broken '-away, of a package of my dental investment 55 compound, in which package, the container takes the form of` a friction top can. Fig. 2 is a side elevation, partly broken away, of the package shown in Fig. 1.

Fig. 3 is a diagrammatic illustration ofthe 60 essential parts which I preferably utilize in effecting an initial compaction vof a dental investment compound in a container.

' Fig. 4 is a view similar to Fig. 3, showing the initially compacted state of the compound after 35 the compressing plunger has compacted it and vbeen removed.

Fig. 5 is a diagrammatic illustration of a second step which I preferably use, in the type of container shown, for finally compacting the ma- 70 Vterial in the container.

Fig. 6 is a vertical section of the same container with a compound finally compacted therein and with the funnel removed, the container being left in the clampingunit.

"75`- Fig. 7 is al perspective view, partlybroken away,

of .the clamping'unitl shown in the'preceding compounds in larger containers, such as 100 pound drums. 10

Fig. 10 is a vertical section of a package produced in accordance with the method illlustrated in Fig: 9. v In the drawings and referring particularly to Figs. 1 to 8,'inclusive, there is shown a container i5 I which is generally known as a friction top container. This container is substantially cubical and has a top wall 2 which is provided with a circularopening 43. A closure for this circular opening is shown at l and, as will be well 20 understood, this closure is designed to fit tightly within each opening and be held firmly therein by frictional contact.

The compound is designated A and, mounted in a depression in the top ofthe compound is a cylindrical box B containing a roll of asbestos paper which is commonly furnished the customer with each package of the compound. for his use in certain operations in forming the molds from the compound. Literature containing instructions for the use of the compound and variousdatamayalsobeplacedintheboxas illustrated at C.'

In the preferred method of producing my package with a container of the type indicated, the container with its top removed is preferably mounted in a clamping unit comprising a base I with a raised portion l substantially identical in area with the base of the container. Cooperating with this base is a clamping unit em- 40 bodying L-shaped members 1 and 8 which I hinge together as as i. These L-shaped members are preferably provided at those edges opposite their hinged edges with handles Il and il which a8- sume parallel relation when the clamping unit is closed. The handle Il preferably has, pivotallv mounted thereon. a hook-likev member I2 which hooks over the handle member I l for holding thev clamping unit closed. The top edges of the clamping members 'I and l are provided with 50 inwardly extending L-shaped lugs i3 with horizontal legs whose lower surfaces are at a slightly higher'level than the top edges ofl the clamping members.

d Designed for cooperation with this clamping unit is a fimnel Il, shown in Figs. 3 and 4. Like- 'wise designed for cooperation therewith are plungers It and I1 which are shown respectively in Figs. 3 and 5 and which may be actuated by a suitable type of actuating means.

In producing my package with the type of container described, the container is mounted within the clamping unit, as illustrated in Fig. 3. Like-v` wise, the funnel Il is mounted within the clamping unit so that itsbase flange il rests upon the top wall 2 of the container I while the cylindrical portion of the funnel registers with the circular opening I of the top wall of the container and is in concentric relation therewith. .m

'I'he properly mixed vcompound is then introduced into the container through the'funnel in such volume that a portion of it will extend substantially to the top of the cylindrical wall of the funnel. -'I11en, the plunger I6 is forced down- 75 wardly under such pressure that the compound is initially compacted both immediately below the plunger and spread laterally to the sides thereof and firmly forced upwardly against the under properly mixed compound is then introduced.

through the funnel Il into the container. Then, the plunger I1 is forced downwardly through the funnel to compact this newly added compound. 'I'his plunger l1 compacts theV compound to a final degree and produces a cylindrical depression as -shown at D in Fig. 6, for the reception of the box containing the asbestos paper. It also produces a depression E of somewhat larger diameter than the depression D for the reception of the literature and the superimposed friction top l. l

The package is completed by placing the box B in position, superimposing the literature thereon and then forcing the friction top 4 into firm contact with the literature. The pressure applied by thev friction top is transmitted through the literature and the box to the body of the compound and also, to some extent, to that portion of the compound which surrounds the lower portion; of the friction top. Owing to the pressure applied by the plunger before the top is applied and owing to the pressure applied by the top itself after it is in position, there is produced a package of dental investment compound or other similar material which will reach the con# sumer in a properly mixed state, notwithstanding the various forces to which it is subjected in handling or shipping.

In the somewhat modiiled form of package, il- L lustrated in Figs. 9 and 10, the roll of asbests paper and the container therefor are normally omitted. Furthermore, I preferably use only one application of pressure for compacting the material in the container. The containers which'are filled in this way are preferably those designed for shipment of the compound in 25 pound and 100 pound lots. v

The preferred method of producing such packages is illustrated in Fig. 9. It involves the use of a cylindrical funnel or tube 20 which is of substantially identical diameter with the container 2l. This funnel or tube 20 may be held in concentric registering relation with the container 2i by depending nngers y22 of the tube 20. It will be noted that the container hasstraight side Y walls. v

'I'he plunger which I preferably use is of frustoconical form and its ybase is of substantially the same diameter as the interior diameter of the container 2i. 'Ihis plunger is provided with a series of ducts 23 extending from the base thereof to the atmosphere. The lower ends of these ducts with one-way flap valves 2l, so that the compound will not enter the ducts, though the air may pass into the space between the base of the plunger and the compound, as this plunger is lifted from the compound after completion of its compressive action, thus preventing formation of a partial vacuum and consequent lifting of upperlayers of the compound.

After the plunger has been forced downwardly under suilicient pressure to adequately compress the compound within the container, it is withdrawn and the funnel or tube 20 is removed, preferably, literature is placed upon the top of the compressed compound and the closure 2l is fas- 3 tened upon the container in such a way that it applies pressure to the literature and consequently to the compound beneath.

It will be seen that I have provided a package of dental investment compound which, pro` viding the compound has been placed in the container in a properly mixed state,.will insure that this compound will reach the consumer in its properly mixed state. The vpressure applied by the plungers is sumcient to prevent any material settling thereafter and the pressure applied by the closure is sumcient to maintain the compound against any material stratification or mlgration of the grains of the material under disturbing forces. The. resulti is that, when the dentist or laboratory technician opens the container preparatory to use of the compound, any portion that he may select therefrom will contain the proper constituents uniformly distributed therethrough in proper percentages to insure that he will obtain proper setting expansion, proper thermal expansion, proper setting time, and proper crushing strength. .as well as proper relative percentages of different grain sizes to insure neness of detail and proper strength and porosity of the mold, if the compound is to be used for casting molds.

is not limited to dental investment compounds.

It lwill be applicable to other compositions of granular material which may differ in grain size, grain shape or specific gravity, wherever itis desirable to maintain the various ingredients properly distributed throughout the mass during handling or shipping. It is also to be understood that the invention is not limited to the particular method or steps of the method herin described for producing the package, as conceivably other ways of producing the same may be employed within the spirit and scope of the appended claims.

I-Iaving thus described my invention, what I claim is:

1. A'package of material comprising a sealed container and iiller therein consisting of a granular compound of different materials which differ in grain size-shape or specific gravity stored therein in a definitely mixed state to insure uniform conditions of distribution of various batches that may be removed for use from said' container under various conditions to which such material is to be subjected in the use thereof, said material being packed in the container under such pressure as will substantially prevent alteration of itsvinitial state of mixture under disturbing forces and with the walls of said container exerting suicient pressure against all sides of the material to maintain it against the action of such forces substantially in its initial packed state.

2. A dental investment material package comprising a container, a ller of investment material in said container in the form of agranular compound of different materials which differ in grain size, shape and specic gravity and which are stored therein in a definitely mixed state to insure specific and uniformreactions of various batches that may be removed from said container under the various conditions to which such compounds are subjected in the use thereof, said mixture be ing packed with the'container under such pressure as will maintain it against alteration, of its initial state of mixtureunder disturbing forces, and a closure -for said container bearing on the material and coacting with the walls of the container to exert suilicient pressure upon said packed material to maintain it substantially in its initial packed state against the action of such forces. 3. A dental investment material package comprising a container provided in its upper wall with an opening to receive a friction top, a illler of investment material packed in said vcontainer in the form of a granular'compound of different ,materials which diii'er in grain size, shape and specific gravity and which are packed therein in a deilnitely mixed state to insure specific and uniform reactions of various batches that may be removed from said container under the various conditions to which such compounds are subiected in the use thereof, said mixture being packed under such pressurewithin and against the walls of the container as will maintain it against alteration of its initial state of mixture against disturbing forces, and a friction top sealing said opening and having a portion projecting into the container and cooperating with the walls of the container to exert sumcient pressure against all sides ofthe material to maintain it in its initial packed state.

4. A dental investment material package comprising a container, a filler of investment material contained therein in the form of a granular compound of dierent materials which differ in grain size, shape and specific gravity and which are packed therein in a definitely mixed state to insure speciilc and uniform reaction of all parts of the material in said container under the various conditions to which such compositions are subjected in the use thereof said mixture being packed under such pressure as will maintain it against migration of its components from their initial state of mixture, and said container having sealing means cooperating with its walls in the "sealed condition of the container to exert sufflcient pressure upon such packed material to maintain it against the action of disturbing 'forces substantially Vin its initial packed state.

5. A granular material package comprising a container provided in one of its wallswith a illling and discharge opening, a nller packed in said container in the form of a granular compoimd of different materials which differ in grain size, shape and specific gravity and which are packed therein in a definitely mixedl state to ensure specic and uniform reactions of various batches that may be removed from said container under the various conditions to which such compounds are subjected in the use thereof, said mixture being packed under such pressure within and against the walls of the container as will maintain it against alteration of its initial state of mixture against disturbingforces, and 'a closure for material and cooperating with the walls of the container to `exert suillcient pressure against all sides of the material to maintain it in its initially packed state.

6. The method of illling containers with pulverulent or granular homogeneous -mixtures of heterogeneous materials of different specific -gravities for the purpose of maintaining the homogeneity of the mixture in a predetermined mixed state for a specified use and preventing separation of the components thereof from such state according to their different specific gravities through forties exerted during the handling or shipment of thepackage, which consists in compounding a mixture having predetermined physical properties i'or aspecliled use and packing smesso l thematerialinacontainerinthiepredeterminedv v nical action and which tend to separate under dismixedstateunderpressureofadegreetoren-4 der the components of the material self-nippertingagainststratiflcation shiftingfrom thepre, determined mixed state under disturbing forces. s

7. The method of packing in wntainers dental investment compounds in the formvof granular aggregates of different materials which differ in grain size, shape or specific gravity and which are so mixed as to insure specinc' and uniform reactions ofall parts of the compound in said container under the various conditions to which such compomtions are subjected in the use thereof and whereby stratification separation of the components of theV packed mixture under disturbing forces is prevented. which comprises compoimding a mixture having predetermined physical properties for a speciiled use, introducing the corn-Y pound into the container in the properly mixed state, applying suillcient pressure to the mixture in the container to compact it to a degree that will substantially prevent migration of the grains and stratiilcation separation of the componentsv of the compound from their initial properly mixed state under disturbing forces. and then sealing 25 the container so as to maintain the packed material in such compacted state. 8. The method of packing in containers dental investment compounds in the form of granular aggregates of diiferent materials which diifer in'30 4 compositions are subjected in the use thereof, and .'23V

whereby stratification separation of the components of the packed mixture under disturbing forces is prevented, which comprises compounding a mixture having predetermined physical properties for a specified use, -introducing the compound into the container in the properly mixed state, applying sumcient pressure to they mixture in the container to compact it t'o a degree that will substantially prevent migration of the grains and stratification separation of the components of the compound from their initial prop-V erly mixed state under disturbing forces, and then applying a closure to such container sothat it exerts sumcient pressure upon such packed materials to maintain it substantially in its initial compacted state.

9. The method of illling containers with pulverulent or granular compounded mixtures of ma- Y terials of a precise composition for designed techturbing forces, for the purpose of maintaining the mixture in a predetermined mixed statefor a specified use and preventing separation of the components thereof from such state through' forces exerted during the handling or shipment of the package, which consists in packing the material in a container in the predetermined mixed state under pressure of a degree to hold it uniformly mixed, each portion having an analysis substantially in accordance with its originally compounded state, and then sealing the container by closure means exerting pressure on the material to maintain the mixture in such predetermined mixed'state. ,v

10. The method of packing in containers .den- 70 tal investment compounds and other like blendedhomogeneous mixtures of solid dry heterogeneous v materials of dlerent specific gravities and/or different grain sizes, normally tendingy in a certain smeer rreeness to separate unser agitation into 75,

their classication strata, so as to maintain the homogeneosity of the mixture during handling or shipment movements of the packed container tending to cause such agitation and separation of the components of the mixture, which consists in compounding the mixture in a predetermined blended homogeneous state packing the mixture in the container in such state until the container is tightly lled under an applied packing pressure proportioned with regard to characteristics of the mixture to a. degree to cause each grain thereof to be supported against separating forces with a. generally equalized pressure from other surrounding grains from top to bottom of the mixture, and then sealing the container to maintain the equalized support of the grains.

PAUL FRANCIS COLLINS. 

